Putting a roof over your wings

Managing construction of a hangar or leasing an existing one isn't as easy as you might think. You may face obstacles ranging from local zoning laws to FAA regulations to insurer mandates. Here's what you need to consider.

First, determine whether land is available for purchase or must be leased from airport authorities. Annual lease fees usually aren't onerous and often include services such as snowplowing and lawn mowing. However, some leases have clauses that transform the hangar you've built into airport property upon lease termination. Not only is this basically a public "taking," it will also make the hangar difficult to sell if the need arises. The cleanest solution is to own the dirt unless property taxes are particularly confiscatory.

Next comes zoning. Your airport manager, architect, consulting engineer and contractor can all be helpful here, particularly if they already have good working relationships with the local zoning committee. Additionally, some states mandate approval before construction can commence at state-owned airports.

When determining how much hangar space you'll require, you should obviously look at the dimensions of the aircraft you'll be housing. Most hangar builders advise figuring out what you need now and then doubling it-not just in terms of size, but also lighting, wiring and office and lounge space.

Consider the activities that will be performed at your hangar, such as type and frequency of maintenance and need for storage and back shops, flight planning and pilot offices, conference rooms, galleys and passenger lounges. If you're planning a small hangar, you may be tempted to save money by skipping on plumbing. Resist this or at least rough-in the pipes now. Think about the solvents, oil and fuel. Even if zoning doesn't require it, you should equip all hangars with emergency eyewash capability. Windows and drive-in delivery doors on the sides and back may not seem needed now but will be appealing later, especially if you're in a climate where the outside temperature sinks to 10 below zero-opening that big hangar door so a delivery truck can drive through lets in a lot of cold air.

Today's aircraft shelters can be equipped with automatic water and foam fire-suppression systems, automatic lighting and computerized environmental controls that precisely regulate temperature and humidity. How much of this is enough generally depends on your climate, the size of the aircraft you fly now and what you are likely to be flying down the road.

You also need to consider style. Corporate operations with one or two aircraft often find the slanted-roof, spine-truss design appealing. These hangars are short and wide, with a roof that slopes down to the back. Simple and truss hangars can accommodate slightly larger operations and usually feature a pitched roof, while even larger operations frequently use arch-span and cantilevered designs.

Inherent with the style of hangar you select is the choice of doors. Doors basically come in four styles: bifold, biparting, overhead and stacking. If snow is a factor, bifold generally offers the best choice. They also don't take up interior roof space when retracted; they fold up and out. Aluminum bifold doors are fairly lightweight and durable but pricy. Electric motors for bifold doors can power cable, chain or belt drives. (A smart option here is to select a remote-controlled electric door opener.) Bifold doors are generally limited to 100-foot widths. Overhead doors work much like those in your garage and tend to be impractical for wide spans. Both biparting and stacking tracked sliding doors can present special maintenance concerns regardless of the climate and are usually manually operated. Stacking sidewall doors are prone to come off their tracks. Top-mounted rails guide many models of tracking doors.

Whatever door you choose, make sure it fits the structure and that the building's frame is strong enough to support it. It also is a help if your building contractor has a good working relationship with the door manufacturer.

On metal sheet exterior walls, specify stainless screws to prevent rust stains. You may also want to consider pre-coated polyester paint panels. And, depending on your hangar's position, or if it's one of several co-joined hangars, local fire code may specify wall burn-through requirements.

As for car parking locations, try to put them away from pitched roofs if you are building in a climate where snow is a factor. Chunks of snow and ice can cascade down the slippery metal roof onto cars-or worse, onto pedestrians.

As part of the basic hangar structure, make sure that footings and floors are metal reinforced and poured deep enough to accommodate structural loads, including those generated by high winds and the weight of present and future aircraft. When planning floor finishes, keep in mind that almost all floor coatings contain polyurethane and epoxy and have a gloss finish. This can make them slippery, especially when wet, so you'd be wise to include fine sand grit to prevent slip and fall accidents. Depending on hangar size, the floor may also need to be trenched and drained to accommodate built-in foam fire suppression systems.

Whatever heating, ventilating and air-conditioning system you choose, use lots of insulation and include adequate roof vents and fans and reversing ceiling fans to efficiently distribute air and minimize moisture.

Be sure that lighting controls are zoned for efficiency. Don't neglect outdoor lighting as part of your security plan. Other systems to consider are electrical or sonic bug and vermin zappers, built-in compressed air, suspended electrical outlets, overhead cranes, a fireproof records vault, locking parts cribs, overhead fire sprinklers and hard wiring for alarm, computer, security cameras and telephone systems. You may also need a perimeter fence and security gate.

If you're leasing or purchasing an existing hangar, ensure that you aren't liable for environmental site remediation necessitated by activities of previous tenants. This includes asbestos abatement and soil and water remediation, which are prime problems in former military hangars. Virtually all military bases operated with few or no environmental restrictions. Also, when the military cedes these hangars to an airport authority, the buildings often need repairs and upgrading. Bottom line: former military hangars may look like bargains but rarely are. Some used civilian hangars aren't, either. Shared or community hangars are also popular, but take care to ensure that the owner or operator has adequate "hangar tender" insurance.

Thoroughly investigate permissible hangar uses as governed by the local airport authority, particularly when it comes to aircraft maintenance, as this may drive your airport and hangar selection.

A final note: When running the numbers, don't assume that the value of a hangar will appreciate. As an investment, a hangar is often a poor value, except in locations where building space is minimal. It is best to treat your hangar like any other piece of depreciating capital equipment justified by need rather than to count on a theoretical future value.

Why are hangars called "hangars?"

The name "hangar" for a structure dedicated to storage of aircraft has been traced to a northern French dialect, although the word's exact origin remains murky. Some French dictionaries state that "hangar" can be used to describe an outbuilding, such as one used to store carriages, while others say it means "cattle pen."

According to one story, when French aviation pioneer Louis Bleriot crash-landed in northern France in the early 1920s, he stored his airplane in a farmer's steel cattle pen to protect it. Bleriot was apparently so taken with this arrangement that he contacted the company that constructed the pen and ordered three more "hangars" for his airplanes. That company, Reid Steel, has been in the hangar construction business ever since, today building structures big enough to house even the enormous Airbus A380.ç